How to add UI for your RAG?!?

Just built some FastAPI SSE backend streaming LLM responses token-by-token, after i got some free time. Two things broke in production that worked fine locally 🙃: nginx buffers SSE by default. The stream was delivering locally, dead silent on Railway. proxy_buffering off, two hours later, fixed. The LLM API returns an empty_retrieval event when no docs match. I wasn't handling it, so the frontend sat on a loading spinner indefinitely. Added the handler, resolved.…